Accomplishments to date (Jan 1, 1973 - Octo 30, 1973) include: (1) Observations that chronic uremia leads to maturational defects in bone mineral and collagen; (2) documentation that 25-hydroxycholecalciferol has a direct effect on bone mineralization independent of parathyroid hormone and absorbed intestinal calcium; (3) detailed analyses of nuclear and mitochondrial protein synthesis in the intestine of chronically uremic animals; (4) documentation of decreased cortical and trabecular bone mass in non-icteric chronic alcoholic patients; (5) the development of an assay for the vitamin D dependent calcium binding protein of human intestine which is applicable to the small amount of tissue obtainable from per oral intestinal biopsy.